Interaction between humans and machines is improved when the user has an increased intuitive understanding of how the machine is operating. In general, tactile (haptic) feedback is responsible for the detection of, but not limited to, roughness, temperature, and/or vibrations. Haptic, or tactile, technology recreates the sense of touch by applying forces, vibrations, or motions to the user. This mechanical stimulation can be used to assist in the creation of virtual objects in a computer simulation, to control virtual objects, and to enhance the remote control of machines and devices.
The field of surgery provides a common scenario where a human is controlling a mechanical device requiring care and dexterity. In a robotic surgery scenario, a surgeon often holds an object of interest through robotic grippers, for example. Without any type of haptic feedback, a surgeon has a reduced understanding of the force being imparted onto object to hold, to avoid damaging the object. Current MIS and medical systems have limited ability to provide force feedback to a surgeon while performing teleoperated surgical tasks. Surgeons are at a disadvantage due to the lack of haptic (tactile) feedback and may be unable to reduce tissue damage during surgeries and diagnostics. Tissue damage often occurs due to the application of excessive force during tissue holding or inappropriate suturing.
Auditory, visual, shear, and vibration feedback have been used to translate force information in teleoperated robotic MIS in research literature. Research studies on robotic surgeries have shown that alternative sensory information can enhance surgeon's performance in teleoperated tasks as compared to the performance with no haptic feedback.
Frequently, a user of robotic or other types of mechanical devices is controlling the device through the use of a stylus, controller, or remote. In particular applications, the user may utilize fingertips to engage the controls of the stylus, controller, or remote. Fingertips can be a good appendage with which to utilize cutaneous feedback since the fingertip skin is replete with mechanoreceptors. The mechanism of providing the information by these receptors to the brain is known as “cutaneous feedback.” Cutaneous-type haptic feedback has been utilized in earlier research for the evaluation of peg-insertion task performance using robotic grippers. But previous uses of cutaneous feedback have failed to provide adequate results.
Vibrating actuators have been used to create cutaneous feedback. These systems induce vibrations on the fingertip skin. Vibrating actuators or vibrotactile sensors do not provide the lack of feedback regarding directional information. Vibrating actuators can only display frequency of a given signal, and thus, are limited in the ability to convey relative and dynamic changes in the operation of the device to the user.
Pin-type haptic feedback has also been used. For example, binary structures have been used as types of pin devices but these binary structures have only two modes of effects, namely protruding and recessed. Shear stress has also been utilized for tactile feedback.